1. Field of Invention
The present invention relates to detergent compositions that not only effectively cleanse the hair but also impart superior wet stage and dry stage conditioning properties to the hair in a single application. The present invention is further directed to a novel delivery system for delivering benefit agents onto and/or into the surface of the skin, nails, and/or hair, and methods of using such systems.
2. Background of the Invention and Prior Art
Consumers often desire to have a hair shampoo that not only effectively cleanses the hair, but that also imparts other desirable properties, such as conditioning and lathering, to the hair. Because nonionic, amphoteric and zwitterionic surfactants are relatively inferior cleansing surfactants in comparison to anionic surfactants, hair shampoos generally are formulated with the latter, which thoroughly cleanses as opposed to conditions the hair. Hence, hair that has been shampooed with an anionic surfactant-based composition usually appears unconditioned and is considered to be cosmetically unappealing. Furthermore, anionic surfactants adversely leave the hair with an undesirable harsh and “dry to the touch” feel, which is difficult to comb in either the wet or dry state. Even after complete drying, such thoroughly cleansed hair remains unsatisfactory in hair softness and “flyaway” properties. Thus, it is usually necessary to perform a post-shampoo conditioning step to such hair in order to ameliorate these undesirable physical characteristics.
With the advent of so-called “two-in-one” conditioning shampoos, it became possible to condition and cleanse hair simultaneously. However, it is well known that the formulation of such “two-in-one” conditioning shampoos is difficult due to the inherent incompatibility between the cleansing anionic surfactants and the cationic conditioning agents. Unfortunately, those known “two-in-one” conditioning shampoos that have overcome the incompatibility problem disadvantageously possess inferior cleansing and conditioning properties.
One known method for reducing the incompatibility between the anionic surfactants and the cationic conditioning agents is through the use of alternative, non-anionic surfactants and improved cationic conditioning agents. However, such alternative, non-anionic surfactants possess relatively inferior cleansing properties.
Other efforts have concentrated on varying the types of conditioners. Cationic conditioning agents disadvantageously do not generally provide optimal overall conditioning benefits, particularly in the areas of “softness” and “wet/dry combing”, when delivered as an ingredient in a shampoo composition. Water-insoluble conditioning agents, such as the non-volatile silicones that are well recognized in the art as providing a degree of softness to the hair, often results in unstable “two-in-one” formulations. See U.S. Pat. No. 4,704,272; U.S. Pat. No. 4,741,855; and U.S. Patent RE 34,584. Substantive cationic polymers, which are capable of depositing on the hair shaft during shampooing to impart the desired degree of manageability, disadvantageously result in formulations that give the hair a greasy feeling or “build-up” on hair. See U.S. Pat. No. 5,221,530; U.S. Pat. No. 5,417,965; U.S. Pat. No. 4,292,212; and U.S. Pat. No. 4,472,297.
Another important property of cleansing compositions that is desired by consumers is lathering. Consumers often associate high lathering with effective cleansing, and typically prefer high lathering shampoos to low lathering shampoos from an aesthetic standpoint. Unfortunately, many therapeutic shampoos, in particular those possessing therapeutic agents such as anti-dandruff agents, contain active agents that tend to adversely affect lathering performance. It is well known that the deposition of therapeutic agents on the hair or skin may be improved via significantly increasing the levels of therapeutic agents in the shampoo compositions. However, not only does the use of such high levels therapeutic agents disadvantageously increase raw materials costs, but also it also reduces the latherability of the shampoo and deleteriously affects product stability. The presence of detergents in the anti-dandruff shampoos also interferes with the ability of therapeutic agents to deposit onto the hair because the detergents are designed to carry or remove oil, grease, dirt, and particulate matter from the hair and scalp during rinsing.
Accordingly, it would be highly desirable to find a “two-in-one” cleansing composition capable of effectively cleansing and detangling the hair while imparting superior wet and dry combing and softness thereto, without creating “build-up”. It would also be desirable to have a high-lathering “two-in-one” cleansing composition that not only effectively cleansed the hair but also deposited a significant amount of therapeutic agents onto the hair and skin.